*** My material ***
In the purpose to test new scripts/apps, I am owning for short time subscription a second remote server (VPS)
that has LAMP and distro Ubuntu 16.04 installed.

*** OPENEMM install fails ****
I choosed to set Sendmail SMTP as its default MTA, but I can't pursue the installation of OpenEMM because the terminal outputs "command not found" in reply to command entry "alternatives --set mta /usr/sbin/sendmail.sendmail".

This entry is shown on page 5 (section 3.1) of this OpenEMM install guide : http://docdro.id/Bur7vwj
And however I did correctly followed and executed the previous instructions (shown below), the terminal still outputs "command not found"